Method and apparatus for absorbing mechanical shock

Abstract

PCT No. PCT/US87/00618 Sec. 371 Date Dec. 9, 1988 Sec. 102(e) Date Dec. 9, 1988 PCT Filed Mar. 18, 1987 PCT Pub. No. WO88/06983 PCT Pub. Date Sep. 22, 1988.A method and apparatus for absorbing mechanical shock is disclosed. The apparatus comprises a pressure cylinder forming a working chamber having first and second portions operable to store damping fluid. The apparatus further comprises a first sensor for generating a first electrical signal in response to the difference in pressure between the damping fluid in the first and second portions of the working chamber. A second sensor is also provided which is able to generate a second electrical signal in response to the movement of the body of the automobile. A computer is used for generating an electrical control signal in response to the first and second electrical signals. Finally, the apparatus further comprises a solenoid for regulating the flow of damping fluid between the first and second portions of the working chamber in response to the output of the computer.

What is claimed is: 
     
       1. A direct acting hydraulic shock absorber for damping the movement of the body of an automobile comprising: a pressure cylinder forming a working chamber having first and second portions operable to store damping fluid;   a piston disposed within said pressure cylinder between first and second portions of said pressure cylinder;   a piston support member mechanically communicating with said piston;   first sensor means for determining the difference in pressure between the damping fluid in said first and second portions of said working chamber so as to sense rebound and compression of said shock absorber, said first sensor means operable to generate a first electrical signal in response to the difference in pressure between the damping fluid stored in said first and second portions, said first sensor means being disposed within said piston support member;   second sensor means for determining the vertical velocity of the body of said automobile, said second sensor means operable to generate a second electrical signal in response to the movement of the body of said automobile, said second sensor means being disposed within said piston support member;   means for generating an electrical control signal in electrical control signal being responsive to whether said shock absorber is in compression or rebound and whether the vertical velocity of the body of said automobile exceeds a predetermined value, and flow of damping fluid between said first and second portions of said working chamber in response to said electrical control signal.   
     
     
       2. The shock absorber as set forth in claim 1, wherein said first sensor means comprises a pressure sensor having a first surface communicating with the damping fluid stored in said first portion of said working chamber, said pressure sensor further having a second surface communicating with the damping fluid stored in said second portion of said working chamber. 
     
     
       3. The shock absorber as set forth in claim 1, wherein said second sensor means comprises an accelerometer. 
     
     
       4. The shock absorber set forth in claim 1, wherein said electrical controllable flow means comprises a solenoid, said solenoid operable to regulate the flow of damping fluid between said first and second portions of said working chamber. 
     
     
       5. A shock absorber of claim 4, wherein said means for generating said electrical control signal comprises a signal conditioning circuit operable to amplify said first and second electrical signals. 
     
     
       6. The shock absorber of claim 5, wherein said means for generating an electrical control signal further comprises a computer electrically communicating with said signal conditioning circuit, said computer operable to generate an output in response to the output of said signal conditioning circuit. 
     
     
       7. The shock absorber of claim 6, wherein said means for generating an electrical control signal further comprises a solenoid driving circuit operable to convert the output of said computer into said electrical control signal which may be used to energize said solenoid. 
     
     
       8. The shock absorber of claim 7, wherein said solenoid driving circuit is operable to convert the output of said signal conditioning circuit into said electrical control signal which may be used to energize said solenoid. 
     
     
       9. A direct acting hydraulic shock absorber for damping the movement of the body of an automobile comprising: a pressure cylinder forming a working chamber having first and second portions operable to store damping fluid;   a piston disposed within said pressure cylinder between first and second portions of said pressure cylinder;   a piston support member mechanically communicating with said piston;   first sensor means for determining the difference in pressure between the damping fluid in said first and second portions of said working chamber so as to sense rebound and compression of said shock absorber, said first sensor means being disposed within said piston support member;   second sensor means for determining the vertical velocity of the body of said automobile, said second sensor means operable to generate a second electrical signal in response to the movement of the body of said automobile, said second sensor means being disposed within said piston support member;   means for generating first and second electrical control signals in response to said first and second electrical signals;   first electrical controllable flow means for regulating the flow of damping fluid into said first portion of said working chamber in response to said first electrical control signal, said first electrical controllable flow means being at least partially disposed within said piston; and   second electrical controllable flow means for regulating the flow of damping fluid into said second portion of said working chamber in response to said second electrical control signal, said second electrical controllable flow means being at least partially disposed within said piston, said first and second electrical controllable flow means being operable to regulate the flow of damping fluid through said piston in response to whether the vertical velocity of the body of said automobile exceeds said predetermined value and whether said shock absorber is in compression or rebound.   
     
     
       10. The shock absorber as set forth in claim 9, wherein said first sensor means comprises a pressure sensor having a first surface communicating with the damping fluid stored in said first portion of said working chamber, said pressure sensor further having a second surface communicating with the damping fluid stored in said second portion of said working chamber. 
     
     
       11. The shock absorber as set forth in claim 9, wherein said second sensor means comprises an accelerometer. 
     
     
       12. The shock absorber set forth in claim 9, wherein said first electrical controllable flow means comprises a first solenoid, said first solenoid operable to regulate the flow of damping fluid into said first portion of said working chamber. 
     
     
       13. The shock absorber set forth in claim 12, wherein said second electrical controllable flow means comprises a second solenoid, said second solenoid operable to regulate the flow of damping fluid into said second portion of said working chamber. 
     
     
       14. The shock absorber as set forth in claim 13, wherein said means for generating first and second electrical control signals comprises a signal conditioning circuit operable to amplify the outputs from said first and second sensor means. 
     
     
       15. The shock absorber as set forth in claim 14, wherein said means for generating first and second electrical control signals further comprises a computer electrically communicating with said signal conditioning circuit, said computer operable to generate an output in response to the output from said signal conditioning circuit. 
     
     
       16. The shock absorber as set forth in claim 15, wherein said means for generating first and second electrical control signals further comprises a solenoid driving circuit operable to convert the output from said computer into voltage levels which may be used to energize said first and second solenoids. 
     
     
       17. The shock absorber of claim 16, wherein said solenoid driving circuit being further operable to convert the output from said signal conditioning circuit into an output which may be used to energize said first and second solenoids. 
     
     
       18. A method for regulating the flow of damping fluid between first and second portions of the working chamber of a direct acting hydraulic shock absorber disposed between the sprung and unsprung portions of a vehicle, said shock absorber having a piston disposed between said first and second portions of said working chamber and a piston support member mechanically communicating with said piston, said method comprising the steps of: sensing the pressure differential between said first and second portions of said working chamber to determine whether said shock absorber is in compression or rebound, said step of sensing the pressure differential including the step of recording the output of first sensor means disposed within said piston support member;   sensing the vertical movement of the sprung portion of said vehicle by recording the output of second sensor means disposed within said piston support member;   determining whether the vertical velocity of the body of said automobile exceeds a predetermined value;   regulating the flow damping fluid between said first and second portions of said working chamber through said piston in response to whether the vertical velocity of the body of said automobile exceeds a predetermined value and whether said shock absorber is in compression or rebound.   
     
     
       19. The method of claim 18, wherein said step of sensing the pressure differential between said first and second portions comprises the step of recording the output of a pressure sensor in fluid communication with said first and second portions of said working chamber. 
     
     
       20. The method of claim 19, wherein said step of sensing the vertical movement of the sprung portion of said vehicle comprises the step of recording the output from an accelerometer. 
     
     
       21. The method of claim 20, wherein said step of regulating the flow of damping fluid between said first and second portions of said working chamber comprises the step of delivering damping fluid from said first and second portions to an electrical controllable flow means for regulating the flow of damping fluid between said first and second portions of said working chamber. 
     
     
       22. The method of claim 21, wherein said electrical controllable flow means comprises a solenoid, said solenoid operable to regulate the flow of damping fluid between said first and second portions of said working chamber. 
     
     
       23. The method of claim 22, wherein said step of regulating the flow of damping fluid between said first and second portions of said working chamber comprises the step of delivering the outputs from said pressure sensor and said accelerometer to a signal conditioning circuit operable to amplify the outputs from said pressure sensor and said accelerometer. 
     
     
       24. The method of claim 23, wherein said step of regulating the flow of damping fluid between said first and second portions of said working chamber further comprises the step of delivering the output of said signal conditioning circuit to a computer electrically communicating with said signal conditioning circuit, said computer operable to generate an output in response to the output of said signal conditioning circuit. 
     
     
       25. The method of claim 24, wherein said step of regulating the flow of damping fluid between said first and second portions of said working chamber further comprises the step of delivering the output from said computer to a solenoid driving circuit operable to convert the output of said computer into voltage levels which may be used to energize said solenoid. 
     
     
       26. The method of claim 25, wherein said step of regulating the flow of damping fluid between said first and second portions of said working chamber further comprises the step of delivering the output from said signal conditioning circuit to said solenoid driving circuit operable to convert the output from said signal conditioning circuit into voltage levels which may be used to energize said solenoid. 
     
     
       27. A method for regulating the flow of damping fluid between first and second portions of the working chamber of a direct acting hydraulic shock absorber disposed between the sprung and unsprung portions of the vehicle, said shock absorber having a piston disposed between said first and second portions of said working chamber and a piston support member mechanically communicating with said piston, said method comprising the steps of: sensing the pressure differential between said first and second portions of said working chamber to determine whether said shock absorber is in compression or rebound, said step of sensing the pressure differential including the step of recording the output of first sensor means disposed within said piston support member;   sensing the vertical movement of the sprung portion of said vehicle by recording the output of second sensor means disposed within said piston support member;   determining whether the vertical velocity of the body of said automobile exceeds a predetermined value;   regulating the flow of damping fluid into said first portion of said working chamber by a first electrical controllable flow means for regulating the flow of damping fluid into said first portion of said working chamber; and   regulating the flow of damping fluid into said second portion of said working chamber by a second electrical controllable flow means for regulating the flow of damping fluid into said second portion of said working chamber, said first and second electrical controllable flow means being operable to regulate the flow of damping fluid through said piston in response to whether the vertical velocity of the body of said automobile exceeds said predetermined value and whether said shock absorber is in compression or rebound.   
     
     
       28. The method of claim 27, wherein said step of sensing the pressure differential between said first and second portions comprises the step of recording the output from a pressure sensor in fluid communicating with said first and second portions of said working chamber, said pressure sensor operable to sense the pressure differential between the damping fluid in said first and second portions of said working chamber. 
     
     
       29. The method of claim 28, wherein said step of sensing the vertical movement of the sprung portion of said vehicle comprises the step of recording the output of an accelerometer. 
     
     
       30. The method of claim 29, wherein said first electrical controllable flow means comprises a first solenoid, said first solenoid operable to regulate the flow of damping fluid into said first portion of said working chamber. 
     
     
       31. The method of claim 30, wherein said second electrical controllable flow means comprises a second solenoid, said second solenoid operable to regulate the flow of damping fluid into said second portion of said working chamber. 
     
     
       32. The method of claim 31, wherein said step of regulating the flow of damping fluid into said first portion of said working chamber comprises the step of delivering the output from said pressure sensor and said accelerometer to a signal conditioning circuit operable to amplify the outputs from said pressure sensor and said accelerometer. 
     
     
       33. The method of claim 32, wherein said step of regulating the flow of damping fluid into said first portion of said working chamber further comprises the step of delivering the output from said signal conditioning circuit to a computer electrically communicating with said signal conditioning circuit, said computer operable to generate an output inresponse to the output of said signal conditioning circuit. 
     
     
       34. The method of claim 33, wherein said step of regulating the flow of damping fluid into said first portion of said working chamber further comprises the step of delivering the output of said computer to a solenoid driving circuit operable to convert the output of said computer into voltage levels which may be used to energize said first solenoid. 
     
     
       35. The method of claim 34, wherein said solenoid driving circuit being further operable to convert the output of said signal conditioning circuit into an output which may be used to energize said first solenoid. 
     
     
       36. The method of claim 35, wherein said solenoid driving being further operable to convert the output of said computer into voltage levels which may be used to energize said second solenoid. 
     
     
       37. The method of claim 36, wherein said solenoid driving circuit being further operable to convert the output of said signal conditioning circuit into an output which may be used to energize said second solenoid. 
     
     
       38. A shock absorber for damping the movement of the body of an automobile relative to a wheel of said automobile, said shock absorber having a pressure cylinder with a reciprocating piston disposed therein operable to divide the working chamber formed by said pressure cylinder into first and second portions, said piston mechanically communicating with a piston support member, said shock absorber comprising: first valve means for controlling the flow of damping fluid between said first and second portions of said working chamber during compression;   second valve means for controlling the flow of damping fluid between said first and second portions of said working chamber during rebound;   first sensor means for determining the difference in pressure between said first and second portions of said working chamber so as to sense rebound and compression, said first sensor means being disposed within said piston support member;   second sensor means for determining the vertical velocity of the body of said automobile, said second sensor means being disposed within said piston support member;   electrical controllable flow means operable to control the actuation of said first and second valve means;   a first flow path between said first and second portions of said working chamber through said electrical controllable flow means;   a second flow path between said second portion of said working chamber and said first valve means through said electrically controllable flow means; and   means for controllably actuating said electrical controllable flow means being operable to regulate the flow of damping fluid through said piston in response to whether the vertical velocity of the body of said automobile exceeds said predetermined value and whether said shock absorber is in compression or rebound.   
     
     
       39. The shock absorber of claim 38, wherein said piston support member comprises an axially extending piston rod mechanically communicating with an end fitting, said end fitting operably securing said piston rod to said body of said automobile, said piston being secured to said piston rod by a piston post fixedly secured to said piston rod. 
     
     
       40. The shock absorber of claim 39, wherein said piston rod has an externally threaded end portion adopted to threadably engage an internally threaded central bore portion of said piston post. 
     
     
       41. The shock absorber of claim 39, wherein said piston has a central bore operable to receive said piston post. 
     
     
       42. The shock absorber of claim 39, wherein said piston post comprises a radially extending step portion, said shock absorber further comprising a first spring disposed between said step portion of said piston post and said first valve means, said first spring operable to bias said first valve means against said piston. 
     
     
       43. The shock absorber of claim 42, wherein said shock absorber further comprises a piston retaining nut operable to secure said piston to said piston post, said piston retaining nut having an internally threaded central bore operable to threadably engage an external threaded end portion of said piston post. 
     
     
       44. The shock absorber of claim 43, further comprising a second spring disposed between a radially extending flange on said piston retaining nut and said second valve means, said second spring means operable to bias said second valve means against said piston. 
     
     
       45. The shock absorber of claim 44, wherein said piston comprises a valve body having a first surface perpendicular to the axis of reciprocation of said piston, said first surface having a first recessed portion. 
     
     
       46. The shock absorber of claim 45, wherein said valve body further comprises a second surface perpendicular to the axis of reciprocation of said piston, said first surface having a second recess portion. 
     
     
       47. The shock absorber of claim 46, wherein said first recess portion and said first valve means are operable to form a first pressure chamber, said first valve means operable to increase the flow of damping fluid between said first and second portions of said working chamber during compression of said shock absorber when said pressure in said first pressure chamber exceeds the pressure in said first portion of said working chamber. 
     
     
       48. The shock absorber of claim 47, further comprising a first sealing element disposed within said first pressure chamber, said first sealing element being operable to prevent damping fluid in said first pressure chamber to flow into said first portion of said working chamber. 
     
     
       49. The shock absorber of claim 48, further comprising a first annular retaining ring disposed within said first pressure chamber, said first annular retaining ring being operable to prevent displacement of said first sealing element with respect to said first valve means. 
     
     
       50. The shock absorber of claim 47, wherein said second recess portion and said second valve means are operable to form a second pressure chamber, said second valve means operable to increase the flow of damping fluid between said first and second portions of said working chamber during rebound of said shock absorber when said pressure in said first pressure chamber exceeds the pressure in the second portion of said working chamber. 
     
     
       51. The shock absorber of claim 50, further comprising a second sealing element disposed within said second pressure chamber, said second sealing element operable to prevent damping fluid in said second pressure chamber to flow into said second portion of said working chamber. 
     
     
       52. The shock absorber of claim 51, further comprising a second annular retaining ring disposed within said second pressure chamber, said second annular retaining ring operable to prevent displacement of said second sealing element with respect to said second valve means. 
     
     
       53. The shock absorber of claim 47, wherein said electrical controllable flow means comprises a solenoid. 
     
     
       54. The apparatus of claim 53, wherein said solenoid comprises a sealing plate having a central flow passage and a plurality of radially displaced flow passages, said central flow passage being in fluid communication with said second portion of said working chamber and said radially displaced flow passages being in fluid communication with said second pressure chamber. 
     
     
       55. The shock absorber of claim 54, wherein said solenoid further comprises an armature operable to engage said sealing plate when said solenoid is closed. 
     
     
       56. The shock absorber of claim 55, wherein said armature is operable to prevent the flow of damping fluid between said central flow passage and said radially displaced flow passages when said solenoid is closed. 
     
     
       57. The shock absorber of claim 56, wherein said solenoid further comprises a spring operable to bias said armature in a direction opposing said sealing plate. 
     
     
       58. The shock absorber of claim 57, wherein said armature has a central bore operable to permit damping fluid from said second portion of said working chamber to flow therethrough. 
     
     
       59. The shock absorber of claim 58, wherein said solenoid further comprises a solenoid housing and a housing cap, said housing cap having an axial flow passage in fluid communication with said central bore of said armature. 
     
     
       60. The shock absorber of claim 59, wherein said piston further comprises an annular member disposed within said piston post between said piston rod and said solenoid housing. 
     
     
       61. The shock absorber of claim 60, wherein said annular member has an axial flow passage and a radially extending flow passage, said radially extending flow passage permitting fluid communication between the first portion of said working chamber and said axial flow passage through a flow passage in said piston post. 
     
     
       62. The shock absorber of claim 61, wherein said pressure sensor has a first surface communicating with said axial flow passage of said annular member, said pressure sensor having a second surface in fluid communication with the axial flow passage in said housing cap. 
     
     
       63. The shock absorber of claim 62, wherein said valve body comprises a first plurality of vertical flow passages operatively associated with said first and second valve means to permit damping fluid to flow from said first portion of said working chamber to said second portion of said working chamber when the pressure of the damping fluid in said first portion of said working chamber is greater than the pressure of the damping fluid in said second portion. 
     
     
       64. The shock absorber of claim 63, wherein said valve body comprises a second plurality of vertical flow passages, said second plurality of vertical flow passages operatively associated with said first and second valve means to permit damping fluid to flow from said second portion of said working chamber to said first portion when the pressure of the damping fluid in said second portion is greater than the pressure of the damping fluid in said first portion. 
     
     
       65. The shock absorber of claim 64, wherein said first flow path comprises a flow passage between one of said second plurality of vertical flow passages in said valve body and said second pressure chamber, said first flow path further comprising a flow passage in said valve body mating with a flow passage in said piston post operable to allow damping fluid in said second pressure chamber to flow into said radially displaced flow passages in said sealing plate. 
     
     
       66. The shock absorber of claim 65, wherein said first flow path further comprises said radially displaced flow passages in said sealing plate. 
     
     
       67. The shock absorber of claim 66, wherein said second flow path comprises a flow passage between said first pressure chamber and said second pressure chamber, said second flow path further comprising said flow passage in said valve body mating with a flow passage in said piston post. 
     
     
       68. The shock absorber of claim 67, wherein said second flow path further comprises said radially displaced flow passages in said sealing plate. 
     
     
       69. The direct acting shock absorber for damping the movement of the body of an automobile comprising: a pressure cylinder forming a working chamber with first and second portions operable to store damping fluid;   a piston disposed within said pressure cylinder between said first and second portions of said working chamber, said piston in fluid communicating with said second portion of said working chamber;   means for supporting said piston within said pressure cylinder, said means for supporting said piston being in fluid communication communicating with said first portion of said working chamber;   first sensor means for determining the difference in the pressure between the damping fluid in said first and second portions of said working chamber so as to sense rebound and compression, said first sensor means operable to generate first electrical signal in response to the difference in pressure between the damping fluid stored in said first and second portions, said first sensor means being disposed within said means for supporting said piston;   second sensor means for determining the vertical velocity of the body of said automobile, said second sensor means operable to generate a second electrical signal in response to the movement of the body of said automobile, said first sensor means being disposed within said means for supporting said piston;   means for generating electrical control signal in response to said first and second electrical signals, said electrical control signal being responsive to whether said shock absorber is in compression or rebound and to whether the vertical velocity of the body of said automobile exceeds a predetermined value; and   electrical controllable flow means for regulating the flow of damping fluid between said first and second portions of said working chamber through said piston in response to said electrical control signal.   
     
     
       70. The shock absorber of claim 69, wherein said means for supporting said piston comprises a piston post with a central bore, said piston post having a flow passage between said first portion of said working chamber and said central bore. 
     
     
       71. The shock absorber of claim 70, wherein said apparatus further comprises an annular member disposed within said piston post, said annular member having a flow passage in fluid communication with first flow passage in said piston post and said first sensor means. 
     
     
       72. The shock absorber of claim 71, wherein said first sensor means being in mechanical communication with said annular member. 
     
     
       73. The shock absorber of claim 72, wherein said electrical controllable flow means includes a flow passage in fluid communication with the second portion of said working chamber, said first sensor means in fluid communication with said flow passage in said electrical controllable flow means. 
     
     
       74. A shock absorber for damping the movement of the body of an automobile, said shock absorber having a piston supported by a piston support member, said shock absorber comprising: a pressure cylinder forming a working chamber having first and second portions operable to store damping fluid;   first sensor means for determining the difference in pressure between the damping fluid in said first and second portions of said working chamber, said first sensor means operable to generate a first electrical signal in response to whether the shock absorber is in compression or rebound, said first sensor means being disposed within said support member;   second sensor means for determining movement of the body of said automobile, said second sensor means operable to generate a second electrical signal in response to the vertical movement of the body of said automobile, said first sensor means being disposed within said piston support member;   means for generating an electrical control signal in response to said first and second electrical signals, said means for generating an electrical control signal operable to record the output of said first sensor means and determine whether said shock absorber is in compression or rebound, said means for generating an electrical control signal being further operable to determine whether the vertical velocity of the body of said automobile exceeds a predetermined value;   first electrical controllable flow means for regulating the flow of damping fluid between said first and second portions of said working chamber through said piston, said first electrical controllable flow means disposed within said pressure cylinder and being operable to regulate the flow of damping fluid during compression of said shock absorber; and   second electrical controllable flow means for electrically regulating the flow of damping fluid between said first and second portions of said working chamber through said piston in response to said electrical control signal, said second electrical controllable flow means disposed within said pressure cylinder and being operable to regulate the flow of damping fluid during the rebound of said shock absorber.   
     
     
       75. The shock absorber of claim 74, wherein said first electrical controllable flow means comprises a first solenoid, said first solenoid operable to regulate the flow of damping fluid into said first portion of said working chamber. 
     
     
       76. The shock absorber of claim 75, wherein said second electrical controllable flow means further comprises a second solenoid, said second solenoid operable to regulate the flow of damping fluid into said second portion of said working chamber. 
     
     
       77. The shock absorber of claim 76, wherein said means for generating an electrical control signal comprises signal conditioning circuit operable to amplify the outputs from said first and second sensor means. 
     
     
       78. The shock absorber of claim 77, wherein said means for generating an electrical control signal comprises a computer, said computer operable to generate an output in response to the output of said signal conditioning circuit. 
     
     
       79. The shock absorber of claim 78, wherein said means for generating an electrical control signal further comprises a solenoid driving circuit operable to convert the output of said computer into voltage levels which may be used to energize said first solenoid. 
     
     
       80. The shock absorber of claim 79, wherein said solenoid driving circuit is further operable to convert the output of said signal conditioning circuit into an output which may be used to energize said first solenoid. 
     
     
       81. The shock absorber of claim 80, wherein said solenoid driving circuit is further operable to convert the output of said computer into voltage levels which may be used to energize said second solenoid. 
     
     
       82. The shock absorber of claim 81, wherein said solenoid driving circuit is further operable to convert the output of said signal conditioning circuit into an output which may be used to energize said second solenoid. 
     
     
       83. The shock absorber of claim 74, wherein said shock absorber further comprises a valve body and a first and a second valve disk biased against opposing surfaces of said valve body, said valve body having a first plurality of vertical flow passages operatively associated with said first and second valve disks to permit damping fluid to flow from said first position of said working chamber to said second portion of said working chamber when the pressure of the damping fluid in said first portion of said working chamber is greater than the pressure of the damping fluid in said second portion. 
     
     
       84. The shock absorber of claim 83, wherein said valve body further comprises a second plurality of vertical flow passages, said second plurality of vertical flow passages operatively associated with said first and second valve disks to permit damping fluid to flow from said second portion of said working chamber to said first portion of said working chamber when the pressure of the damping fluid in said second portion is greater than the pressure of the damping fluid in said first portion. 
     
     
       85. The shock absorber of claim 84, wherein said valve body further comprises a first recessed portion cooperating with said first valve disk to create a first pressure chamber, said first solenoid operable to selectively increase the pressure inside said first pressure chamber so as to create a pressure differential on opposing sides of said first valve disk. 
     
     
       86. The shock absorber of claim 85, wherein said valve body further comprises a second recessed portion cooperating with said second valve disk to create a second pressure chamber, said second solenoid operable to selectively increase the pressure inside said second pressure chamber so as to create a pressure differential on opposing sides of said second valve disk. 
     
     
       87. The shock absorber of claim 86, wherein said first solenoid permits selective fluid communication between said first pressure chamber and said first portion of said working chamber when said solenoid is open. 
     
     
       88. The shock absorber of claim 87, wherein said second solenoid permits selective fluid communication between said second pressure chamber and said second portion of said working chamber. 
     
     
       89. The shock absorber of claim 88, wherein said first plurality of vertical flow passages is in fluid communication with said first pressure chamber. 
     
     
       90. The shock absorber of claim 89, wherein said second plurality of vertical flow passages is in fluid communication with said second pressure chamber. 
     
     
       91. A method for regulating the flow of damping fluid through a piston disposed between the first and second portions of the working chamber of the direct acting shock absorber, said piston being supported in said working chamber by a piston support member, said shock absorber operable to damp movement of the body of an automobile, said method comprising the steps of: recording the output of a first sensor means for determining the difference in pressure between the damping fluid in said first and second portions of said working chamber so as to determine whether said shock absorber is in compression or rebound, said first sensor means operable to generate a first electrical signal in response to the difference in pressure between the damping fluid stored in said first and second portions of said working chamber, said first sensor means being disposed within said piston support member;   recording the output of a second sensor means for determining the vertical velocity of a body of said automobile, said second sensor means operable to generate a second electrical signal in response to the movement of the body of said automobile, said second sensor means being disposed within said piston support member;   generating an electrical control signal in response to said first and second electrical signals, said electrical control signal being responsive to whether said shock absorber is in compression or rebound and to whether the vertical velocity of the body of said automobile exceeds a predetermined value; and   regulating the flow of damping fluid through said piston by an electrical controllable flow means in response to said electrical control signal.   
     
     
       92. The method of claim 91, wherein said first sensor means comprises a pressure sensor having a first surface communicating with a damping fluid stored in said first portion of said working chamber, said pressure sensor further having a second surface communicating with the damping fluid stored in said second portion of said working chamber. 
     
     
       93. The method of claim 91, wherein said second sensor means comprises an accelerometer. 
     
     
       94. The method of claim 91, wherein said electrical controllable flow means comprises a solenoid, said solenoid operable to regulate the flow of damping fluid between said first and second portions of said working chamber. 
     
     
       95. The method of claim 91, wherein said piston comprises a valve body and a first and a second valve disk biased against opposing surfaces of said valve body, said valve body having a first plurality of vertical flow passages operatively associated with said first and second valve disks to permit damping fluid to flow from said first portion of said working chamber to said second portion of said working chamber when the pressure of the damping fluid in said first portion of said working chamber is greater than the pressure of the damping fluid in said second portion. 
     
     
       96. The method of claim 95, wherein said valve body comprises a second plurality of vertical flow passages, said second plurality of vertical flow passages operatively associated with said first and second valve disks to permit damping fluid to flow from said second portion of said working chamber to said first portion of said working chamber when the pressure of the damping fluid in said second portion is greater than the pressure of the damping fluid in said first portion. 
     
     
       97. The method of claim 96, wherein said electrical controllable flow comprises a solenoid, said solenoid is operable to selectively create a pressure differential on opposing sides of said first valve disk thereby counter-biasing said first valve disk. 
     
     
       98. The method of claim 97, wherein said solenoid is further operable to selectively create a pressure differential on opposing sides of said second valve disk thereby counter-biasing said second valve disk. 
     
     
       99. The method of claim 98, wherein said valve body further comprises a first recessed portion cooperating with said first valve disk to create a first pressure chamber, said solenoid operable to selectively increase the pressure inside said first pressure chamber so as to create a pressure differential on opposing sides of said first valve disk. 
     
     
       100. The method of claim 99, wherein said valve body further comprises a second recessed portion cooperating with said second valve disk to create a second pressure chamber, said solenoid operable to selectively increase the pressure inside said second pressure chamber so as to create a pressure differential on opposing sides of said second valve disk. 
     
     
       101. The method of claim 100, wherein said shock absorber further comprises a piston post operable to support said valve body. 
     
     
       102. The method of claim 101, wherein said solenoid further comprises a sealing plate, said sealing plate having a central flow passage and a plurality of radially displaced flow passages, said central flow passage being in fluid communication with said second portion of said working chamber, said radially displaced flow passages being in fluid communication with said second pressure chamber through a flow passage in said valve body and a flow passage in said piston post. 
     
     
       103. The method of claim 102, wherein said first pressure chamber is in fluid communication with said second pressure chamber. 
     
     
       104. The method of claim 103, wherein said second pressure chamber is in fluid communication with at least one of said second plurality of vertical flow passages. 
     
     
       105. The method of claim 104, wherein said solenoid further comprises an armature operable to engage said sealing plate when said solenoid is closed. 
     
     
       106. The method of claim 105, wherein said armature is operable to prevent the flow of damping fluid between said central flow passage and said radially displaced flow passages when said solenoid is closed. 
     
     
       107. The method of claim 106, wherein said solenoid further comprises a spring is operable to bias said armature in a direction away from said sealing plate. 
     
     
       108. The method of claim 107, wherein said armature has a central bore operable to permit damping fluid from said second portion of said working chamber to flow therethrough. 
     
     
       109. The method of claim 108, wherein said solenoid further comprises a solenoid housing and a housing cap, said housing cap having an axial flow passage in fluid communication with said central bore of said armature. 
     
     
       110. The method of claim 109, wherein said piston further comprises an annular member disposed within said piston post between said piston rod and said solenoid housing. 
     
     
       111. The method of claim 110, wherein said annular member has an axial flow passage and a radially extending flow passage, said radially extending flow passage permitting fluid communication between the first portion of said working chamber and said axial flow passage through a flow passage in said piston post. 
     
     
       112. The method of claim 111, wherein said hock absorber further comprises a pressure sensor, said pressure sensor having a first surface communicating with said axial flow passage of said annular member, said pressure sensor having a second surface in fluid communication with said axial flow passage in said housing cap. 
     
     
       113. The method of claim 112, further comprising an accelerometer disposed on said annular member. 
     
     
       114. A method for regulating the flow of damping fluid between the first and second portions of a direct acting shock absorber, said shock absorber able to damp movement between the body and a wheel of an automobile, said method comprising the steps of: determining whether the frequency of the vertical movement of the body of said automobile is substantially equal to a first predetermined value;   determining whether the frequency of the vertical movement of the wheel of said automobile is substantially equal to a second predetermined value by sensing the difference in pressure between the damping fluid in said first and second portions of said working chamber; and   regulating the flow of damping fluid through a piston disposed between said first and second portions of said working chamber in response to whether the frequency of the body of said automobile is substantially equal to a first predetermined value and whether the frequency of vertical movement of the wheel of said automobile is substantially equal to a second predetermined value.   
     
     
       115. The method of claim 114, wherein said step of determining whether the frequency of the vertical movement of the body of said automobile is substantially equal to said first predetermined value comprises the step of integrating the output of an accelerometer which moves in unison with the body of said automobile. 
     
     
       116. The method of claim 114, wherein said step of determining whether the frequency of the vertical movement of the wheel of said automobile is substantially equal to said second predetermined value comprises the step of recording the pressure differential between said first and second portions of said working chamber and calculating the value of A 2  according to the following equation: ##EQU2## where: P t  is the differential pressure between the upper portion and the lower portion of said working chamber at time t; and T is the period of the natural frequency of the wheel of said automobile.   
     
     
       117. A method for regulating the flow of damping fluid between the first and second portions of a working chamber of a direct acting shock absorber during compression and rebound, said shock absorber operable to damp the movement of the body of an automobile, said method comprising the steps of: recording the output of a pressure sensor disposed between the first and second portions of said working chamber to determine whether said shock absorber is in compression or rebound;   sensing the vertical movement of the body of said automobile;   determining whether the vertical velocity of the body of said automobile exceeds a predetermined value; and   regulating the flow of damping fluid through a piston disposed between said first and second portions of said working chamber in response to whether the vertical velocity of the body of said automobile exceeds said predetermined value and whether said shock absorber is in compression or rebound.   
     
     
       118. The method of claim 117, wherein the step of determining whether the vertical velocity of the body of said automobile exceeds said predetermined value comprises the step of integrating the output of an accelerometer, said accelerometer operable to sense the vertical acceleration of the body of said automobile. 
     
     
       119. The method of claim 117, wherein said step of regulating the flow of damping fluid comprises the step of increasing the flow of damping fluid between said first and second portion of said working chamber during both compression and rebound when the magnitude of the vertical velocity of the body of said automobile is below said predetermined value. 
     
     
       120. The method of claim 119, wherein said step of regulating the flow of damping fluid comprises the step of increasing the flow of damping fluid between said first and second portions of said working chamber during rebound and decreasing the flow during compression when the vertical velocity of the body of said automobile is downward and the magnitude of said vertical velocity exceeds said predetermined value. 
     
     
       121. The method of claim 120, wherein said step of regulating the flow of damping fluid comprises the step of decreasing the flow of damping fluid between said first and second portions during rebound and increasing the flow during compression when the vertical velocity of the body of said automobile is upward and the magnitude of said vertical velocity exceeds said predetermined value. 
     
     
       122. A method for regulating the flow of damping fluid between first and second portions of the working chamber of a direct acting shock absorber having a piston disposed therein, said shock absorber operable to damp the movement of the body of an automobile, said method comprises; recording the output of a pressure sensor disposed between said first and second portions of said working chamber;   determining whether said shock absorber is in compression or rebound by using the output of said pressure sensor;   determining the vertical velocity of said piston disposed within said shock absorber; and   determining whether the vertical velocity of said piston exceeds a predetermined value; and   regulating the flow of damping fluid between said first and second portions of said working chamber in response to the vertical velocity of said piston and whether said shock absorber is in compression or rebound.   
     
     
       123. The method of claim 121, wherein said step of regulating the flow of damping fluid between said first and second portions of said working chamber comprises the step of decreasing the flow of damping fluid between said first and second portions during compression when the magnitude of the vertical velocity of said piston exceeds said predetermined value. 
     
     
       124. The method of claim 123, wherein said step of regulating the flow of damping fluid between said first and second portions comprises the step of decreasing the flow of damping fluid between said first and second portions when the magnitude of the vertical velocity of said piston exceeds said predetermined value. 
     
     
       125. A method for regulating the flow of damping fluid between first and second portions of a working chamber of a shock absorber, said shock absorber operable to damp movement of the body and a wheel of an automobile, said method comprising the steps of: recording the output of a pressure sensor disposed between said first and second portions of said working chamber during a predetermined length of time;   calculating the value of A 2  according to the following equation: ##EQU3## where: P t  is the differential pressure between the first and second portions of said working chamber at time t;   T is the period of the natural frequency of the wheel of said automobile; and decreasing the flow of damping fluid between said first and second portions of said working chamber during compression of said shock absorber when the value of A 2  exceeds a predetermined value.   
     
     
       126. The method of claim 125, further comprising the additional step of decreasing the flow of damping fluid between said first and second portions of said working chamber during rebound of said shock absorber when the value of A 2  exceeds said predetermined value. 
     
     
       127. A method for regulating the flow of damping fluid through a piston disposed between first and second portions of the working chamber of a direct acting hydraulic shock absorber, said piston being supported by a piston support member, said shock absorber being disposed between the sprung and unsprung portions of an automobile, said method comprising the steps of: sensing the pressure differential between said first and second portions of said working chamber so as to permit determination of whether said shock absorber is in compression or rebound by recording the output of first sensor means disposed within said piston support member;   sensing the vertical movement of the sprung portion of said vehicle by recording the output of second sensor means disposed within said piston support member;   determining whether the vertical velocity of the body of said automobile exceeds a predetermined value;   regulating the flow of damping fluid into said first portion of said working chamber by a first electrical controllable flow means for regulating the flow of damping fluid into said first portion of said working chamber; and   regulating the flow of damping fluid into said second portion of said working chamber by a second electrical controllable flow means operable to regulate the flow of damping fluid into said second portion of said working chamber, said first and second electrical controllable flow means being operable to regulate the flow of damping fluid through said piston in response to whether the vertical velocity of the body of said automobile exceeds said predetermined value and whether said shock absorber is in compression or rebound.   
     
     
       128. The method of claim 127, wherein said step of sensing the pressure differential between said first and second portions of said working chamber comprises the step of recording the output from a pressure sensor disposed between said first and second portions of said working chamber, said pressure sensor operable to sense the pressure differential between the damping fluid in said first and second portions of said working chamber. 
     
     
       129. The method of claim 127, wherein said step of sensing the vertical velocity of the sprung portion of said vehicle comprises the step of recording the output of an accelerometer disposed within said shock absorber. 
     
     
       130. The method of claim 127, wherein said first electrical controllable flow means comprises a first solenoid, said first solenoid operable to regulate the flow of damping fluid into said first portion of said working chamber. 
     
     
       131. The method of claim 130, wherein said second electrical controllable flow means further comprises a second solenoid, said second solenoid operable to regulate the flow of damping fluid into said second portion of said working chamber. 
     
     
       132. The method of claim 131, wherein said step of regulating the flow of damping fluid into said first portion of said working chamber comprises the step of delivering the output from said pressure sensor and said accelerometer to a signal conditioning circuit operable to amplify the outputs from said pressure sensor and said accelerometer. 
     
     
       133. The method of claim 132, wherein said step of regulating the flow of damping fluid into said first portion of said working chamber further comprises the step of delivering the output from said signal conditioning circuit to a computer electrically communicating with said signal conditioning circuit, said computer operable to generate an output in response to the output of said signal conditioning circuit. 
     
     
       134. The method of claim 133, wherein said step of regulating the flow of damping fluid into said first portion of said working chamber further comprises the step of delivering the output of said computer to a solenoid driving circuit operable to convert the output of said computer into voltage levels which may be used to energize said first solenoid. 
     
     
       135. The method of claim 134, wherein said solenoid driving circuit is further operable to convert the output of said signal conditioning circuit into an output which may be used to energize said first solenoid. 
     
     
       136. The method of claim 135, wherein said solenoid driving is further operable to convert the output of said computer into voltage levels which may be used to energize said second solenoid. 
     
     
       137. The method of claim 136, wherein said solenoid driving circuit is further operable to convert the output of said signal conditioning circuit into an output which may be used to energize said second solenoid. 
     
     
       138. The method of claim 132, wherein said piston comprises a valve body and a first and a second valve disk biased against opposing surfaces of said valve body, said valve body having a first plurality of vertical flow passages operatively associated with said first and second valve disks to permit damping fluid to flow from said first portion of said working chamber to said second portion of said working chamber when the pressure of the damping fluid in said first portion of said working chamber is greater than the pressure of the damping fluid in said second portion. 
     
     
       139. The method of claim 138, wherein said valve body comprises a second plurality of vertical flow passages, said second plurality of vertical flow passages operatively associated with said first and second valve disks to permit damping fluid to flow from said second portion of said working chamber to said first portion of said working chamber when the pressure of the damping fluid in said second portion is greater than the pressure of the damping fluid in said first portion. 
     
     
       140. The method of claim 139, wherein said valve body further comprises a first recesses portion cooperating with said first valve disk to create a first pressure chamber, said first solenoid operable to selectively increase the pressure inside said first pressure chamber so as to create a pressure differential on opposing sides of said first valve disk. 
     
     
       141. The method of claim 140, wherein said valve body further comprises a second recessed portion cooperating with said second valve disk to create a second pressure chamber, said second solenoid operable to selectively increase the pressure inside said second pressure chamber so as to create a pressure differential on opposing sides of said second valve disk. 
     
     
       142. The method of claim 141, wherein said first solenoid permits selective fluid communication between said first pressure chamber and said first portion of said working chamber when said solenoid is open. 
     
     
       143. The method of claim 142, wherein said second solenoid permits selective fluid communication between said second pressure chamber and said second portion of said working chamber. 
     
     
       144. The method of claim 143, wherein said first plurality of vertical flow passages is in fluid communication with said first pressure chamber. 
     
     
       145. The method of claim 144, wherein said second plurality of vertical flow passages is in fluid communication with said second pressure chamber.